This invention relates to an electrical junction box to be mounted on a motor vehicle or the like and more particularly relates to an electrical junction box that includes a drainage structure.
An electrical junction box such as a fuse box, a relay box, and a junction box may be installed in a vehicle room or an engine room in a motor vehicle while obtaining a suitable space.
Fuses, electronic circuits, and electrical circuit such as connectors are generally found in the electrical junction box. If water enters the electrical junction box, the water may cause some problems such as current leak, short circuit, or the like. Accordingly, it is preferable to prevent water from entering the electrical junction box. However, because electrical wires are generally arranged in the electrical junction box to connect electrical circuits in the electrical junction box to external electrical circuits, the electrical junction box cannot be fully sealed.
If water should enter the electrical junction box, it is preferable to drain the water rapidly to avoid serious damage to the electrical circuits. In view of this purpose, JP HEI 11(1999)-187539 A has proposed an electrical junction box in which a drainage hole is provided in a bottom portion.
However, in the case where the electrical junction box is installed in the engine room, there will be possibility that water splashed during moving in rain or car-washing may enter the electrical junction box.
In order to overcome the above problems, there will be ideas of providing a special waterproof wall on the drainage hole or providing a check valve in the drainage hole. However, these ideas will involve a complicated structure and difficulty in production, and the electrical junction box will be larger on account of the water proofing wall or the check valve. It is difficult to realize these ideas.